An assessment of the current epidemiological and laboratory capacities for influenza‐like illnesses and severe acute respiratory infection surveillance, Yemen 2022

Abstract Background and Objectives We aim to re‐activate influenza sentinel surveillance system in Yemen after disruption related to repurposing for COVID‐19 pandemic. WHO Country Office (CO) in collaboration with Yemen's Ministry of Public Health and Population (MOPH&P) jointly conducted an assessment mission to assess the current situation of the influenza sentinel surveillance system and assess its capacity to detect influenza epidemics and monitor trends in circulating influenza and other respiratory viruses of epidemic and pandemic potential. This study presents the results of the assessment for three sentinel sites located in Aden, Taiz, and Hadramout/Mukalla. Methodology A mixed methods approach was used to guide the assessment process and to help achieve the objectives. Data were collected as follows: desk review of the sentinel sites records and data; interviews with stakeholders, including key informants and partners; and direct observation through field visits to the sentinel sites, MOPH&P and the Central Public Health Laboratory (CPHL). Two assessment checklists were used: assessment of sentinel sites for SARI surveillance, and checklist for assessment of availability of SARI sentinel surveillance. Results and Conclusion COVID‐19 has affected health systems and services, and this was demonstrated in this assessment. The influenza sentinel surveillance system in Yemen is not effectively functional; however, there is plenty of room for improvement if investment in the system's restructuring, training, building technical and laboratory capacities, and conducting continuous and regular supervision visits.


| INTRODUCTION
The conflict in Yemen entered its eighth year with the resulting humanitarian crisis in terms of food security, people in need, and displacements. 1 The health system has collapsed with serious shortages of medicines and medical supplies and shattered essential services that are unable to accommodate, provide or respond to the needs of the populations. [2][3][4][5][6] Furthermore, the COVID-19 pandemic has added an extra burden to health systems in Yemen and globally. The pandemic has highlighted the need to maintain essential public health functions and services. It has also highlighted the critical role of public health professionals in combating epidemics and pandemics. 7,8 Influenza surveillance in Yemen was initially introduced in 2010 following the H1N1 outbreak by setting up two sentinel sites for Severe Acute Respiratory Infection (SARI) in collaboration with NAMRU-3 9 and World health Organization (WHO). In 2014 and 2021, the influenza sentinel surveillance system expanded to include another three sentinel sites in Taiz, Hodeida, and Hadramout-Mukalla following the support that from the Pandemic Influenza Preparedness (PIP) Framework Partnership Contribution Funds. 2 The objective of the SARI/influenza-like illnesses (ILI) surveillance system is the following: strengthen the influenza surveillance mechanisms in the country in order to provide forewarning of outbreaks and emergence of novel influenza virus; expand the laboratory surveillance of influenza for confirmation of ILI and use it to estimate the proportion of these cases that are due to influenza; provide viral isolation to the WHO Influenza Reference Laboratory for antigenic analysis to detect new strains and for vaccine formulation; and, firm up national vaccine policy based on the local circulating influenza virus. 3 In order to re-activate the influenza surveillance system after repurposing it for the COVID-19 pandemic, to improve influenza case detection and monitoring of influenza epidemics, and to monitor trends in circulating influenza viruses, the WHO in collaboration with Yemen's Ministry of Public Health and Population (MOPH&P) led a mission to conduct an assessment of the current situation of epidemiological and laboratory surveillance in Yemen. The focus of this mission was related to the influenza surveillance system's capacity to detect and monitor influenza epidemics and to monitor trends in circulating influenza viruses. The following work presents the results of the assessment for three sentinel sites located in Aden, Taiz, and Hadramout/Mukalla.

| Design
A mixed methods approach was used to guide the assessment process and to help achieve study objectives. Data were collected from the following sources: desk review of the sentinel sites records and data; interviews with key stakeholders, including informants and partners; direct observation through field visits to the sentinel sites, MOPH&P and the Central Public Health Laboratory (CPHL).

| Data collection
Two assessment checklists were used for the purpose of this assessment: 'Assessment of sentinel sites for SARI surveillance' (see

| Ethical considerations
Approval to conduct the study was given by the Ministry of Public Health and Population in Yemen-Aden.

| RESULTS
At present, sentinel data are collected from inpatient departments at the sentinel sites. The information collected is minimal and includes number of consultation of SARI cases by age group and clinical/ laboratory data, which include the following: date of onset, date of specimen collection, and date of testing. All sentinel sites are committed to send their SARI report to the CPHL and MOPH&P on a weekly basis. Selected sites are both SARI and ILI sites but currently ILI enrolment of cases is not functional yet and so there are no specimens collected from outpatient departments.

| National, provincial, and field level(s) influenza surveillance system in Yemen
Information communication between various administrative levels is a great drawback; the flow of information from the field to provinces is inconsistent at best. This incompleteness of data is due to inadequate communication and results in poor data analysis, which often does not transpire in the first place, and naturally there are no results to be shared back to provinces and clinics. This generates frustration among the health personal and a sentiment of lack-of-purpose for data collection.
The division of tasks between field, district, and provincial teams is not always clear. In some instances, clinic-based personnel are the ones compiling daily data in weekly reports, whereas in other cases, it is the district monitoring and evaluation personnel that takes on this task. The same issues were observed between district and provincial teams; provincial teams are meant to send weekly compilations to the national team; however, they sometimes do it only monthly and sometimes not at all. At the national level, the personnel in charge of collecting and analyzing data were unable to demonstrate weekly/ monthly/yearly compilations; they were also unable to share calculations of percentages for indicators for each site. Reporting rates were low and data quality was questionable. This is due to the availability of well-trained staff in charge of filling in the SARI forms. Completeness of records in Aden made it feasible for the SARI logbook details for inpatient consultation to be available; data for each calendar year and reporting data for SARI (age, gender, date of onset of symptoms, symptoms and signs, patient temperature, and final diagnosis) were complete. This is unfortunately not the case in Taiz and Mukalla, whereby health personnel find the SARI/ILI data collection to represent a significant added workload especially due to the lack of electronic records or an internet connection; this makes their data recording and registration laborious and time consuming.
The quality of the data collected is quite poor due to incompleteness, and the logbook for SARI data per calendar year is either unavailable or incomplete. Laboratory equipment and infrastructure also differ between both sites; the laboratory in Aden is well equipped with RT-PCR 7500 and refrigerators for sample storage at 4 C and À70 C, though it sometimes runs out of reagents. On the contrary, in Taiz and Mukalla, the hospital does not have a fridge where the sample specimens can be kept, and the laboratory has no capacity to test for influenza by PCR.
The current assessment of the SARI sentinel sites also showed that the feasibility and sustainability of the chosen facilities are suboptimal. This is due to a variety of factors: first and foremost, the lack and incompleteness of efficient, consistent, and sustainable mechanisms for collection, storage, and transport of clinical specimens. This is compounded by the lack of stable and long-term funding to cover hazard pays or incentives for well trained staff, in addition to the general cost of the surveillance operations at the sites and the incapability of the existing infrastructure to cover and facilitate the necessary mechanisms for data reporting.

| Limitations
Due to the security situation and war, the authors would like to caution that the assessment did not include more sites (public and private) from different geographical locations, so the representativeness is limited and cannot be generalized for all Yemeni population. Furthermore, the researchers found that the lack of SARI reagents in the mentioned and assisted sentinel site resulted in constraints to properly assess staff performance and quality of equipment (for example PCR). The researchers also encountered hurdles in relation to the lack of transparency and accountability, which limits SARI data quality.

| Recommendations
In accordance with the insight provided from this assessment in terms of the current situation of epidemiological and laboratory surveillance related to capacity to detect and monitor influenza epidemics and to monitor trends in circulating influenza viruses, a variety of action points for further development are put forward. Primarily, a great deal of investment in training and capacity building is absolutely crucial; trainings workshops can be conducted for surveillance/laboratory staff on SARI/ILI data management and reporting-this should be coupled with training of laboratory personnel to build their capacity to use PCR to test for influenza and to improve the capacity of identified laboratories and surveillance sites, in terms of infrastructure, human and financial resources in order to expand and strengthen the surveillance of influenza. This will not be possible without stable and long-term funding to cover the general cost of the surveillance operations and training.